Based on

Movies like Panienka z poste restante (1935)

Marysia, a postal clerk, travels to Vienna to work as Mr. Olszewicz's secretary as a result of a distorted telegram. Their first joint venture is to sign a contract with American industrialist Smith, pretending to be a young married couple. He takes them to his yacht in Dubrovnik, where he refuses to sign the contract, having guessed the deception and feeling cheated.